• Title/Summary/Keyword: Environment noise condition

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Selective pole filtering based feature normalization for performance improvement of short utterance recognition in noisy environments (잡음 환경에서 짧은 발화 인식 성능 향상을 위한 선택적 극점 필터링 기반의 특징 정규화)

  • Choi, Bo Kyeong;Ban, Sung Min;Kim, Hyung Soon
    • Phonetics and Speech Sciences
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    • v.9 no.2
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    • pp.103-110
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    • 2017
  • The pole filtering concept has been successfully applied to cepstral feature normalization techniques for noise-robust speech recognition. In this paper, it is proposed to apply the pole filtering selectively only to the speech intervals, in order to further improve the recognition performance for short utterances in noisy environments. Experimental results on AURORA 2 task with clean-condition training show that the proposed selectively pole-filtered cepstral mean normalization (SPFCMN) and selectively pole-filtered cepstral mean and variance normalization (SPFCMVN) yield error rate reduction of 38.6% and 45.8%, respectively, compared to the baseline system.

A Study on Drive Characteristic of Photovoltaic to consider temperature compensation account. (온도보정계수를 고려한 태양광발전 운전특성연구)

  • Lee Jeong-il;Yoon Jeong-Phil;Yu Hee-Ok;Yoon Hyung-Sang;Cha In-Su
    • Proceedings of the KIPE Conference
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    • 2001.07a
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    • pp.63-66
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    • 2001
  • Photovoltaic System does military exploit that use heliometer light and is clearness source of energy. Photovoltatic System is no noise, shock among is several Substitute energy and after establishment maintenance having simple special quality, is applied in many fields. However, while Photovoltatic System is having these advantage, but react sensitively in effect of Photovoltaic scanning Quantity, temperature change etc.. surrounding environment, when did not satisfy condition, express indefinite output price. Consider voltage$\cdot$current output measurement value and temperature revision calculation by temperature change of existing photovoltaic system and change of output price of when did Simulation analyzed comparison.

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A convergence analysis of Block MADF algorithm for adaptive noise reduction

  • Min, Seung-gi;Young Huh;Yoon, Dal-hwan
    • Proceedings of the IEEK Conference
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    • 2002.07a
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    • pp.377-380
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    • 2002
  • When it calculates the optimum price of filter coefficient, the many operation quantity is necessary. Is like that the real-time control is difficult and the hardware embodiment expense is big. The case which does not know advance information of input signal or the case where the statistical nature changes with change of surroundings environment is necessary the adaptive filter. Every hour to change a coefficient automatically and system in order to reach to the condition of optimum oneself, the fact that is the adaptive filter. When it does not the quality of input signal or it does not know the environment of surroundings every hour changing, it does not emit not to be, in order to collect, the fact that is the adaptive filter. The case of the Acoustic Echo Canceler does thousands filter coefficients in necessity. It reduces a many calculation quantity to respect, it uses the IIR filter from hour territory. Also it uses the block adaptive filter which has a block input signal and a block output signal. The former there is a weak point where the stability discrimination is always demanded. Consequently, The block adaptive filter is researched plentifully. This dissertation planned the block MADF adaptive filter used to MADf algorithm.

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Analysis of Unsteady Blade Forces in a Vertical-axis Small Wind Turbine (수직형 소형풍력터빈의 비정상 익력 평가)

  • LEE, SANG-MOON;KIM, CHUL-KYU;JEON, SEOK-YUN;ALI, SAJID;JANG, CHOON-MAN
    • Transactions of the Korean hydrogen and new energy society
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    • v.29 no.2
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    • pp.197-204
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    • 2018
  • In the present study, unsteady flow analysis has been conducted to investigate the blade forces and wake flow around a hybrid street-lamp having a vertical-axis small wind turbine and a photovoltaic panel. Uniform velocities of 3, 5 and 7 m/s are applied as inlet boundary condition. Relatively large vortex shedding is formed at the wake region of the photovoltaic panel, which affects the increase of blade torque and wake flow downstream of the wind turbine. It is found that blade force has a good relation to the variation of the angle of attack with the rotation of turbine blades. Variations in the torque on the turbine blade over time create a cyclic fluctuation, which can be a source of turbine vibration and noise. Unsteady fluctuation of blade forces is also analyzed to understand the nature of the vibration of a small wind turbine over time. The detailed flow field inside the turbine blades is analyzed and discussed.

The Current Status and Recommendation of Work Environment Management in Small Scale Industry with less than 5 Workers (경인지역 일부 5인미만 사업장 근로자의 작업환경실태와 관리대책)

  • Kim, Dea Sic;Roh, Youngman;Kim, Hyun Wook;Jeong, Chun Hwa;You, Ki ho
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.11 no.3
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    • pp.179-189
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    • 2001
  • This study was performed to identify the current status of work environment management and to provide appropriate recommendations for small scale industry with less than 5 workers from September, 2000 to October, 2000 in Seoul city and Gyoung-gi province. The 211 companies were surveyed by checklist included the elements of management of work environment, hazardous chemicals, MSDS, personal protective equipment, and ventilation system. The proportion of metal products manufacturing and printing industries are 25.6 % and 22.3%, respectively. The daily working hours in printing industry is longer than others. The industries that produce potentially hazardous agents, such as noise, dust, metal, organic solvents, radiation and chemical material are pulp, plating, machinery, and printing, respectively. In above industries, only 2.8 % of those recognised and had MSDS. The proportion of companies providing fire extinguishers, safety showers are found to be 13.3 %, 7.1 %, respectively. Only 24.2 % of companies provided personal protective equipment to the workers. The ventilation system was operated in most of companies. But local exhaust ventilation system is provided to 22.3 % of those, also had not been annually inspected. This study showed that the current status of occupational safety and health was not appropriate for workers in small scale industries. It is suggested that annual physical examination have to be performed, MSDS usage must become widespread, and employer and emplyees in small scale industry should be educated for the treatment and storage of hazardous chemicals to improve the occupational safety and health of the working environment. also, regulatory standard has to be applied to local exhaust ventilation system in small scale industry to improve the working condition.

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Synergetics based damage detection of frame structures using piezoceramic patches

  • Hong, Xiaobin;Ruan, Jiaobiao;Liu, Guixiong;Wang, Tao;Li, Youyong;Song, Gangbing
    • Smart Structures and Systems
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    • v.17 no.2
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    • pp.167-194
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    • 2016
  • This paper investigates the Synergetics based Damage Detection Method (SDDM) for frame structures by using surface-bonded PZT (Lead Zirconate Titanate) patches. After analyzing the mechanism of pattern recognition from Synergetics, the operating framework with cooperation-competition-update process of SDDM was proposed. First, the dynamic identification equation of structural conditions was established and the adjoint vector (AV) set of original vector (OV) set was obtained by Generalized Inverse Matrix (GIM).Then, the order parameter equation and its evolution process were deduced through the strict mathematics ratiocination. Moreover, in order to complete online structural condition update feature, the iterative update algorithm was presented. Subsequently, the pathway in which SDDM was realized through the modified Synergetic Neural Network (SNN) was introduced and its assessment indices were confirmed. Finally, the experimental platform with a two-story frame structure was set up. The performances of the proposed methodology were tested for damage identifications by loosening various screw nuts group scenarios. The experiments were conducted in different damage degrees, the disturbance environment and the noisy environment, respectively. The results show the feasibility of SDDM using piezoceramic sensors and actuators, and demonstrate a strong ability of anti-disturbance and anti-noise in frame structure applications. This proposed approach can be extended to the similar structures for damage identification.

The Relationship between Noise Exposure Level in Worksite and Workers' Stress Symptoms (산업장의 소음폭로수준과 근로자의 스트레스 증상간의 관련성)

  • Park, Kyung-Ok;Lee, Myung-Sun
    • Journal of Preventive Medicine and Public Health
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    • v.29 no.2 s.53
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    • pp.239-254
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    • 1996
  • Health services on industrial noisy environment have been provided only for noise-induced hearing loss management until now. But gradually, modem diseases and death have come to be related to stress and mental health deeply, therefore noise-induced mental disorder, like a stress became very important. In this point, the purpose of this study was to analyze the relationship between noise exposure level in worksite and workers' stress symptoms. This study included a survey of 786 manual workers selected from 89 worksites in 21 factories in Puchon. The results were as follows: 1. For demographic characteristics, most of the workers were males(80.8%), the $20\sim29years$ old were 34.5% and those who graduated from high school were 65.3%. The workers whose monthly income ranged from 100,000 to 800,000 won were 37.5% and who have a religion were 47.9%. 2. For occupational characteristics, workers who had worked $1\sim5$ years in the factories were 33.0%. Those who were much for them workload were 43.9% and who worked more than 8 hours a day were 73.9%. Those who were disatisfied with their job and pay were 31.9% and 50.6%. The workers who responsed ventilation condition of their worksites were bad were 51.9% and the dissatisfed with working environment of their worksites were 45.9%. 3. Workers who were suffering from tinnitus were 53.3% and those who perceived hearing loss were 50.1%. Persons who reported they always wore earplugs at work were 35.4%. Those who felt earplugs bigger than their ears were 30.6% and those who experienced eardiseases caused by earplugs were 25.6%. 4. For the noise exposure level in worksite, workers who were exposed to $80\sim90dB$ were 30.3%, $90\sim100dB$ were 26.4% and $50\sim70dB$ were 19.2%. 5. Workers' stress symptoms were significantly related to marital status and their monthly income(p<0.05). Workers who were single and had lower monthly income showed higher PSI (Psychiatric Symptom Index) scores than those who were married and had higher monthly income. Higher PSI scores were also significantly related to $1\sim2$ days hight-work per week, much for them workload, dissatisfaction with their job, and bad relationship with their bosses and coworkers. 6. Higher PSI scores were significantly related to severe tinnitus and perceived hearing losso(p<0.001). Workers who felt the earplugs they use did not fit their ears showed significantly higher PSI scores(p<0.01). Workers who reported that they did not feel they need earplugs showed. significantly higher PSI scores (p<0.05). Increased experience of eardisease caused by earplugs that did not fit were also significantly related to higher PSI scores(p<0.01). 7. The higher noise exposure level in worksite from 80dB was, the more severe stress symptoms including PSI subparts were reported; Anxiety, Anger, Depression, and Cognitive disorder(p<0.001). 5. According to the results of stepwise multiple regression analysis, factors affecting workers' PSI scores were perceived hearing loss$(R^2=0.160)$, noise exposure level in worksite$(R^2=0.110)$, realtionship with coworkers, amount of workload, monthly income and relationship with bosses orderly and the total $R^2$ of this 6 factors was 0.371. 9. The most significant factors that have impact on manual workers' stress symptoms were perceived hearing loss and noise exposure level in worksite, especially noise exposure level in the worksite was the most affective factor on the depression symptom.

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Study on Hospital Environmental Causes Affected the Mother′s Comfort After Her Child Birth (산욕부 안위에 영향을 미치는 병원환경 요인에 관한 연구)

  • 변수자
    • Journal of Korean Academy of Nursing
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    • v.8 no.1
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    • pp.1-15
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    • 1978
  • The Purpose of this study is to examine closely the causes influenced upon the comfort and recovery of the woman delivered of a child in the hospital at the same time to understand environmental status of hospitals in order to promote mother's health recovery, and to improve hospital environment by emphasizing the meaning of environment and health before the medical staff and hospital administrative authority. In the method of servery of the research, 165 post paestum patients have been randomly selected who were accommodated and delivered their babies at OB(obstetric ) & GY (Gynecologic) unit the 7 general hospitals for the period of 6 December 1976 through 17 December 1976. As for the survey, it has been used of Questionnaire where we have 65 items in the respect of personal environment in the hospital such as trusting nurse, ability, reliability, kindness and etiquette of nurse and tile character of nurse the relationship with patients the other respect of physical environment included 9f temperature, moisture. air-ventilation lightening noise, cleanness. facilities, and the third realm being of mother's hearth ground to have the following conclusion 1. The feature of the collected personnel they are from OB or GY sects of from OB unit of the other 5 hospitals except the two general hospitals of the college or school Otherwise the rate of the patients to nurses would be 9 : 1. As for the nurses'ground it would be appeared of 20-25 years of age as the 76%. either 3 year course or 4 year course in the education would be each 50% and less than 2 year experience case would record as of 60 %. In the respect of hospital physical environmental status, there we have two hospitals without any thermometers, on the other han4 nowhere there's hygrometer, otherwise, the lightening is normal or over than normal As for the structure of noise protection the corridors're, generally speaking worse than rooms, nerver hueless, there's no ventilating system in the hospitals. The rooms'repainted in white and yellow, light green white, or green color. The patient's clothing were in green pink blue, light green or in white co for. There're not anything special in both decoration and equipments. Most of them used tall beds except in one hospital 2. To the extent of perception of patient's hatch 9round and hospital environment it is presented that they perceived nurse's ability in highest in total human variable, though perceived kindness or etiquette in the lowest otherwise, comparatively high in total average. 3. In the respect of physical environment it is highest perceived of lightening terms, otherwise, lowest perceived of air ventilation and total average became lowest than the one of the original record 4. To ages, in the respect of hatch ground rather old aged mother than the younger one has perceived that nurse would be trusting, in good service character, able, at the same time, liable, Otherwise, in physical environment regardless of age, they perceived lightening in high and remarkably lower in ventilation As a result of the examination of the difference in hospital environment to each age it is appeared of statistical difference at 5% level of ability in the personal environment otherwise little difference as for physical environment 5. In the respect of perceiving level to educational standard it is highly perceived of personal environment for higher ranking group rather than lower group in the educational standard. In case of physical environment it is highly perceived for lower level group rather than higher level group in educational background. The variables which have statistical significance at 5% level are from trusting kindness, etiquette and total kindness, etiquette and total all significance at 5% level are from trusting, kindness, etiquette and total human environment variable in personal environment, otherwise, there's little difference in the physical environment. 6. The perceiving level due to times of admission and accommodation at the hospital would be cleared out as gradual higher perception both physical and personal environment in the hospital. At 5% significant level of the ventilation condition in physical environmental variable it is presented of meaningful difference otherwise, there we have little difference both in Personal variable and other one. 7. In accordance with living standard, the perception degree of personal environment in tee hospital would be inclined to increase to higher living standard on the other hand, in case of the physical environment, the perception level world increase to lower living standard At 5 % level, the trustuariable and total scores in the personal eicuironmectal variable there appeared a meaningful/ significant difference otherwise, there presented little difference both in physical environmental and other variable to the living standard 8. Pertaining to family unit, the mother of an independent family unit perceived highly in all respect of the personal and the physical environment in the hospital rather than the woman of succeeding family unit. At 5 % level there appeared a difference in the respect of kindness and etiquette both in personal environment variable, on the other hand, there hardly marked a difference between other variable and physical environmental one. 9. The degree of perception to comforting level has little connection with a statistical difference the age, educational level hospital admitting times, living standard or family unit. 10. The most effective variable to mother's comforting level will be nurse's ability, reliability, trusting manner, and total physical environment variable in order.

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Experimental Study of Metal Surface Wave Communication for Engine room of Vessels (선박 기관실에서의 금속체 표면파 통신 활용 연구)

  • Jin-Woo Kong;Hak-Sun Kim
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2022.06a
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    • pp.108-109
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    • 2022
  • In this study analyzed experimental data on noise interference caused by engine operating apply surface wave communication in the engine room. For the experiment, 7 areas of the engine room on 256 ton tug boat and measured noise during engine on off using signal analyzer for effect surface wave communication. In order to construct and actual communication network based on the analysis of the noise and confirm the characteristics of surface wave communication in the area made metal bulkheads the actual communication network installed communication equipment between three metal bulkheads and conducted a comparative experiment with wireless communication. The difference was confirmed. As a result, in the case of surface wave communication, there was no significant difference in the transmission and reception rates before and after engine operation in an environment with three bulkheads, but in the case of Wi-Fi using wireless, the performance deteriorated significantly during operation. was confirmed. As a result of analyzing the experimental data, it was confirmed that noise caused by engine operation affects wireless communication but does not affect surface wave communication. Therefore, even in the area with a lot of electromagnetic wave noise in the ship, when the surface wave communication system is configured using the ship's metal structure, it is possible to replace the wireless communication and furthermore, it is possible to apply the surface wave communication in the enclosed space and the engine room in the ship.

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A Survey on the Actual Conditions of Summer Working Uniforms for Contracted Foodservice Workers (위탁급식업체 종사자의 하절기 작업복 착용 실태에 관한 연구)

  • Lee, Hyo-Hyeon;Yeom, Jeong-Ha;Choi, Jeong-Wha
    • Journal of the Korean Society of Clothing and Textiles
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    • v.34 no.4
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    • pp.553-562
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    • 2010
  • This survey investigates the conditions of summer working uniforms for contracted foodservice workers. The data were obtained from 67 workers through in-depth interviews (July 2005~October 2005). The results of study are as follows: The working environment changed to menu and cooking method (air temperature $28\sim37^{\circ}C$, humidity 72~86 %RH, radiant temperature $27\sim37^{\circ}C$, air velocity 0.14~0.37m/sec). They answered that the working environment has high temperatures, humidity, excessive noise, and liability to slide. The typical accidents were burns, cuts, slide, and ligament injuries in the workplace. Work duties consisted of cooking, serving food, washing, and cleaning up leftover food. All the employees carried out multi tasks. The primary working postures and motions were standing, crouching, and lifting. The female workers usually wore underwear (panty and brassiere), upper and lower work wear, aprons, waterproof-aprons, cotton-gloves, rubber-gloves, socks, and rubber-boots. The satisfaction of the uniform was relatively low for trousers and waterproof-aprons. The answer about the fit was generally "comfortable." They answered "back," "chest," and "head" were wet with perspiration during work. The uncomfortable parts were the crotch and neck. Questions concerning their satisfaction with the material of uniforms indicated a high rate of dissatisfaction, particularly for ventilation and absorbency. In case of the colors of the working uniform, workers preferred white color for the upper part, and black color for the lower part.